JP2001110564A - Electroluminescence lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assure an effective manufacture of a Newton ring-free EL lamp which has no influence to transparency and visibility when they contact the flat surface glass. SOLUTION: The EL lamp is formed by laminating in the order from the bottom; a plastic film substrate having good flatness; a 1st conductive layer a fluorescent material layer, a 1st insulating layer, a 2nd conductive layer. The dot spacer designed to dissolve the optical problems of a Newton ring is formed o the plastic film substrate at the other side of contacting the conductive layer of the EL lamp by screen printing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to an electroluminescent lamp, and more particularly to an electroluminescent lamp which is normally generated when the electroluminescent lamp is arranged on a surface reflecting glass or other light. The present invention relates to an electroluminescent lamp which solves the above problem by adding a dot spacer.

[0002]

2. Description of the Related Art Electroluminescent lamps (hereinafter also referred to as EL lamps) have various uses.
It is used as a panel backlight or as another input, a back light source of a display device, or the like. In this case, which is mounted behind or in contact with a flat surface, the EL lamp surface is soft and highly flexible, which may cause an optically inconvenient Newton ring. Newton ring is a general optical phenomenon,
Occurs when a concave transmission surface contacts a flat transmission surface. When using an EL lamp, the surface and the installation surface of the EL lamp are generally both flat. Will be.

[0003] In a device using an EL lamp, a multi-colored irregularly shaped Newton ring appears. This is because both the surface of the EL lamp and the surface on which the lamp is installed (installation surface) reflect light. Because you do. Therefore, the generation of Newton rings can be prevented by reducing reflection or preventing bending of at least one of the two surfaces.
The problem of Newton's rings is not limited to devices using EL lamps, but also exists in, for example, multilayer liquid crystal display devices, touch panels, and other optical devices. Attempts to suppress Newton's rings in these include: (1) Inserting a suitable material between the two surfaces to eliminate the air layer. (2) Matting or etching at least one of the two surfaces. (3) A separator is placed between the two surfaces to separate them. The following method is conceivable.

[0004] In the first method, the space between the two surfaces is filled with an appropriate material whose refractive index matches that of either of the two surfaces to eliminate Newton's rings. Unfortunately, this approach is not suitable when using EL lamps. This is because the presence of such a substance between the EL lamp and the installation surface makes it difficult to view the image of the device using the EL lamp. Further, it is necessary to add a troublesome procedure in the assembling process, and the problem that air bubbles enter the material must be solved. In these respects, it is impractical to apply this method to the equipment using EL lamps.

[0005] The second method is to eliminate Newton's ring by matting or etching one surface. The point of contact between the two surfaces is relatively small,
Since the reflected light is scattered on the processing surface, the generated Newton's ring is very small and cannot be distinguished by human eyes. EL
In the lamp industry, techniques similar to matting and etching techniques have been used. A matte finish was applied to the EL lamp surface to suppress the generation of Newton rings. I can't. Although effective, this matting technique has several other problems. For example, matte finishes tend to scatter some of the light and tend to reduce the quality of the image displayed on the device on which the EL lamp is mounted. In addition, the matte finish impairs transparency, and is a critical defect when an EL lamp is used for an application requiring a transparent surface. Another problem with this approach is that E
It is expensive to apply a special finish to the front surface of the L-lamp.

[0006] A third technique is to use a spacer to make 2
There is a method to keep the distance between two faces constant. For example, in many touch panels, in order to maintain insulation between two electrodes, the intervals are made constant by dot spacers generated using a photoresist method. Although this method does not degrade the image quality, it has problems to be solved, and it has not been used for the solution to the Newton's ring of the conventional EL lamp. For example, if the photoresist method is used to manufacture an EL lamp, the cost is very high. In addition, the size and arrangement of the dot spacers need to be designed so that Newton rings do not occur and that they do not peel off during mounting, and it is also necessary to establish an efficient production method. Therefore, although the third method was the most effective, it was not used for EL.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to efficiently provide an EL lamp which does not affect transparency and visibility even when in contact with a flat surface of glass or the like and which does not generate Newton rings. It is in.

[0008]

As a first means for solving the above-mentioned problems, a dot spacer is provided on the entire outer surface or a part of the light emitting surface of the electroluminescence lamp. As a second solution, the electroluminescence lamp is a plastic film substrate having good smoothness;
A phosphor layer on the first conductive layer; a first insulating layer on the phosphor layer; a second conductive layer on the first insulating layer; a second on the second conductive layer.
An insulating layer; and a first of the plastic film substrates
A configuration was adopted in which a dot spacer formed by screen printing was provided on a surface not in contact with the conductive layer. As a third solution, the height of the dot spacer of the electroluminescence lamp is set to 100 μm or less.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An EL lamp 100 according to the present invention
A first conductive layer 104 is formed on a plastic substrate 102 such as polyester. The plastic substrate is not particularly limited, and any plastic substrate can be used as long as it is used for a conventional transparent conductive film. For example, a surface such as polyethylene terephthalate, polycarbonate, polyether sulfone, etc. may be subjected to processing such as hard coating. Preferably, the substrate is sufficiently smooth.

Next, the first conductive layer 104 is made of ITO (ind)
ium tin oxide) and other metal composite oxides, and are formed by sputtering, vapor deposition, CVD, or other coating methods. Further, the phosphor layer 106 is formed on the first conductive layer 104, and the first insulating layer 108 and the second conductive layer 110 are provided on the phosphor layer 106. Layers other than the first conductive layer 104 are continuously stacked by screen printing. The phosphor layer 106 may be formed by coating the phosphor with a moisture-proof coating to protect the phosphor from deterioration due to ambient moisture. Phosphor layer 106
Emits electroluminescence when excited by electricity.

In some prior arts relating to EL lamps, the second conductive layer 110 is formed of a metal foil, but is preferably formed of carbon or silver. Next, a second insulating layer 112 is formed on the second conductive layer 110. On the surface of the plastic film substrate that is not in contact with the first conductive layer, dot spacers 101 are formed by screen printing.
To form

In order to avoid Newton rings, unlike the attempts made in the prior art, the present invention does not score the substrate and does not cover it with paint or grids. The dot spacer works so that the substrate of the EL lamp keeps a sufficient and constant distance from the installation surface.
The simpler the screen printing process, the lower the manufacturing cost of the EL lamp and the more effective it is to eliminate Newton's rings.

The resin of the dot spacer includes acrylic, epoxy, polyester, urethane and the like.
Transparency is preferred. Dot spacers are added to the illuminated surface outside the EL lamp in a screen printing operation. The thickness of the printed layer of the dot spacer is 100μ so that the EL lamp can be inserted into the housing of the equipment used without any trouble.
m or less, and preferably 80 μm or less.
As the arrangement pitch of the dot spacers (interval between the centers of the dots), a range of 0.5 mm to 2.5 mm can be used, and preferably 1.0 mm to 2.0 mm.

It is desirable that the diameter of the dot spacer does not exceed 30 μm. This diameter is determined by the convenience of the device using the EL lamp. In a preferred embodiment, the EL lamp is suitable for use in a backlight of an LCD panel. A diameter value of 30 μm is the diameter of an LCD pixel in a particular LCD panel. In other words, this LCD
When using an EL lamp, the diameter of the spacer should be LCD
It is desirable that the size be 30 μm or less, which is the size of a pixel.

To efficiently manufacture dot spacers,
It is necessary to produce a screen plate that can form dot spacers having an appropriate size and pitch and that is durable. Although such a screen plate has never been realized in the EL industry, a screen printing plate using a metal mask method is suitable. In the metal mask manufacturing method, there is an etching method, but in order to perform fine processing with high accuracy, an electroforming method in which the wall surface of the hole is excellent in smoothness is preferable. This is because controlling the diameter of the dot spacer is the most important factor in making a commercially acceptable EL lamp for EL lamp-using equipment. In addition, although the manufacturing method of the EL lamp body may be different in lamination and processing methods, the effect of adding a dot spacer is not limited.

[0016]

EXAMPLE In the example, a first conductive layer 104 made of an ITO film was formed on a plastic film substrate 102 made of polyethylene terephthalate by sputtering. The phosphor layer 106 is formed by dispersing a phosphor in a polyester ink, the first edge layer 108 is formed by dispersing barium titanate in a polyester ink, and the second conductive layer 110 is formed by a carbon ink (Acheson The second insulating layer 112 was made of UV insulating ink (manufactured by DuPont), and the dot spacer 101 was made of polyester ink (manufactured by Acheson). Then, the phosphor layer 106, the first insulating layer 108, the second conductive layer 110, the second
Both the insulating layer 112 and the dot spacer 101 were formed by screen printing. Here, in the dot spacer, the height is 50 μm, the diameter is 30 μm, and the vertical and horizontal pitch is 2.0 mm.
Was used. When the EL lamp of the example was attached to the housing of the equipment used, there was no inferior visibility,
No generation of Newton's rings, which had conventionally occurred, was observed.

[Brief description of the drawings]

FIG. 1 is a block diagram of an EL lamp according to the present invention.

[Description of Signs] 100: EL lamp 101: Dot spacer 102: Plastic film substrate 104: First conductive layer 106: Phosphor layer 108: First insulating layer 110: Second conductive layer 112: Second insulating layer

Claims (3)

[Claims] 1. An electroluminescent lamp having dot spacers on the entire outer surface or a part of a light emitting surface. 2. A plastic film substrate having good smoothness;
A first conductive layer on a plastic film substrate; a phosphor layer on the first conductive layer; a first insulating layer on the phosphor layer; a second conductive layer on the first insulating layer; An electroluminescence lamp having a dot spacer formed by screen printing on a surface of the plastic film substrate that is not in contact with the first conductive layer. 3. The electroluminescent lamp according to claim 1, further comprising a dot spacer having a height of 100 μm or less.